Chronic prenatal ethanol exposure increases adiposity and disrupts pancreatic morphology in adult guinea pig offspring.

BACKGROUND: Ethanol consumption during pregnancy can lead to a range of adverse developmental outcomes in children, termed fetal alcohol spectrum disorder (FASD). Central nervous system injury is a debilitating and widely studied manifestation of chronic prenatal ethanol exposure (CPEE). However, CPEE can also cause structural and functional deficits in metabolic pathways in offspring. OBJECTIVES AND METHODS: This study tested the hypothesis that CPEE increases whole-body adiposity and disrupts pancreatic structure in guinea pig offspring. Pregnant guinea pigs received ethanol (4 g kg(-1) maternal body weight per day) or isocaloric-sucrose/pair-feeding (control) for 5 days per week throughout gestation. RESULTS: Male and female CPEE offspring demonstrated growth restriction at birth, followed by a rapid period of catch-up growth before weaning (postnatal day (PD) 1-7). Whole-body magnetic resonance imaging (MRI) in young adult offspring (PD100-140) revealed increased visceral and subcutaneous adiposity produced by CPEE. At the time of killing (PD150-200), CPEE offspring also had increased pancreatic adipocyte area and decreased ß-cell insulin-like immunopositive area, suggesting reduced insulin production and/or secretion from pancreatic islets. CONCLUSION: CPEE causes increased adiposity and pancreatic dysmorphology in offspring, which may signify increased risk for the development of metabolic syndrome and type 2 diabetes mellitus.

Alcohol exposure during late gestation: multiple developmental outcomes in sheep.

Alcohol consumption during pregnancy remains common in many countries. Exposure to even low amounts of alcohol (i.e. ethanol) in pregnancy can lead to the heterogeneous fetal alcohol spectrum disorders (FASD), while heavy alcohol consumption can result in the fetal alcohol syndrome (FAS). FAS is characterized by cerebral dysfunction, growth restriction and craniofacial malformations. However, the effects of lower doses of alcohol during pregnancy, such as those that lead to FASD, are less well understood. In this article, we discuss the findings of recent studies performed in our laboratories on the effects of fetal alcohol exposure using sheep, in which we investigated the effects of late gestational alcohol exposure on the developing brain, arteries, kidneys, heart and lungs. Our studies indicate that alcohol exposure in late gestation can (1) affect cerebral white matter development and increase the risk of hemorrhage in the fetal brain, (2) cause left ventricular hypertrophy with evidence of altered cardiomyocyte maturation, (3) lead to a decrease in nephron number in the kidney, (4) cause altered arterial wall stiffness and endothelial and smooth muscle function and (5) result in altered surfactant protein mRNA expression, surfactant phospholipid composition and pro-inflammatory cytokine mRNA expression in the lung. These findings suggest that fetal alcohol exposure in late gestation can affect multiple organs, potentially increasing the risk of disease and organ dysfunction in later life.

Chronic prenatal ethanol exposure increases glucocorticoid-induced glutamate release in the hippocampus of the near-term foetal guinea pig.

Exposure to high cortisol concentration can injure the developing brain, possibly via an excitotoxic mechanism involving glutamate (Glu). The present study tested the hypothesis that chronic prenatal ethanol exposure (CPEE) activates the foetal hypothalamic-pituitary-adrenal axis to produce high cortisol exposure in the foetal compartment and alters sensitivity to glucocorticoid-induced Glu release in the foetal hippocampus. Pregnant guinea pigs received daily oral administration of ethanol (4 g/kg maternal body weight/day) or isocaloric-sucrose/pair-feeding from gestational day (GD) 2 until GD 63 (term, approximately GD 68) at which time they were euthanised, 1 h after their final treatment. Adrenocorticotrophic hormone (ACTH) and cortisol concentrations were determined in foetal plasma. Basal and electrically stimulated Glu and gamma-aminobutyric acid (GABA) efflux in the presence or absence of dexamethasone (DEX), a selective glucocorticoid-receptor agonist, were determined ex vivo in foetal hippocampal slices. Glucocorticoid receptor (GR), mineralocorticoid receptor (MR) and N-methyl-D-aspartate (NMDA) receptor NR1 subunit mRNA expression were determined in situ in the hippocampus and dentate gyrus. In the near-term foetus, CPEE increased foetal plasma ACTH and cortisol concentrations. Electrically stimulated glutamate, but not GABA, release was increased in CPEE foetal hippocampal slices. Low DEX concentration (0.3 microM) decreased stimulated glutamate, but not GABA, release in both CPEE and control foetal hippocampal slices. High DEX concentration (3.0 microM) increased basal release of Glu, but not GABA, in CPEE foetal hippocampal slices. GR, but not MR, mRNA expression was elevated in the hippocampus and dentate gyrus, whereas NR1 mRNA expression was increased in the CA1 and CA3 fields of the foetal hippocampus. These data demonstrate that CPEE increases high glucocorticoid concentration-induced Glu release in the foetal hippocampus, presumably as a consequence of increased GR expression. These effects of CPEE, coupled with increased glutamate release and increased NMDA receptor expression, may predispose the near-term foetal hippocampus to GR and Glu-NMDA receptor-mediated neurodevelopmental toxicity.

Effects of chronic prenatal ethanol exposure on mitochondrial glutathione and 8-iso-prostaglandin F2alpha concentrations in the hippocampus of the perinatal guinea pig.

It is hypothesised that oxidative stress is a key mechanism of ethanol neurobehavioural teratogenicity, resulting in altered endogenous antioxidant status and increased membrane lipid peroxidation in the hippocampus of chronic prenatal ethanol exposure (CPEE) offspring. To test this hypothesis, timed pregnant guinea-pigs (term, approximately gestational day (GD) 68) received chronic daily oral administration of (i) 4 g ethanol kg(-1) maternal bodyweight, (ii) isocaloric sucrose with pair feeding, or (iii) water. At GD 65 (term fetus) and postnatal day (PD) 0 (neonate), individual offspring were killed, the brain was excised and the hippocampi were dissected. Glutathione (GSH) concentration was measured in the cytosolic and mitochondrial fractions of hippocampal homogenate. The occurrence of lipid peroxidation was determined by measuring the concentration of 8-iso-prostaglandin F2+/- (8-iso-PGF2+/-). There was CPEE-induced decreased brain weight and hippocampal weight at GD 65 and PD 0, decreased mitochondrial GSH concentration in the hippocampus at PD 0, with no change in mitochondrial GSH concentration at GD 65 or cytosolic GSH concentration at GD 65 or PD 0, and no change in mitochondrial or whole-homogenate 8-iso-PGF2+/- concentration in the hippocampus at GD 65 or PD 0. The data demonstrate that CPEE produces selective mitochondrial dysfunction in the hippocampus of the neonatal guinea-pig, involving GSH depletion.

Stabilization of hypoglycosylation in a patient with congenital disorder of glycosylation type Ia.

A follow-up over 7 years on a patient with congenital disorder of glycosylation type Ia showed a significant normalization of hypoglycosylated transferrin. Isoelectric focusing for serum transferrin is a widely used screening method but there could be a limit of detection and the subtle changes can be also overlooked. Re-test with a different method is desirable, especially when the clinical suspicion for congenital disorder of glycosylation is high.

The source of endogenous carbon monoxide formation in human placental chorionic villi.

Carbon monoxide (CO) is proposed to play a role in placental vascular control, as the placenta produces and responds to CO. The mechanism by which CO is formed by the placenta is unclear but could be through heme oxygenase (HO) degradation of heme, lipid peroxidation, or both. Human placental cotyledons were perfused with Kreb s solution to remove blood. Chorionic villi segments were prepared for measurements of CO production in the absence/presence of an exogenous supply of heme substrate (methemalbumin), inhibitors of HO, or inhibitors of lipid peroxidation. HO inhibitors used were chromium mesoporphyrin (CrMP) (0.1 mM, 0.3 mM), and azalanstat (0.1 mM, 0.3 mM). The lipid peroxidation inhibitors used were EDTA (0.1 mM, 0.3 mM) and deferoxamine (0.1 mM). Incubation of villi segments with methemalbumin (0.15 mM, 0.3 mM, 0.45 mM) resulted in a concentration-dependent increase in CO formation above the basal, endogenous rate. CrMP and azalanstat inhibited basal endogenous CO production, whereas EDTA and deferoxamine enhanced CO formation above basal level. These results demonstrate that endogenous CO was formed by human chorionic villi from heme, primarily through the action of HO, and are consistent with the hypothesis that HO plays a role in the regulation of placental vasculature by the formation of heme-derived CO.

Chronic prenatal ethanol exposure alters glucocorticoid signalling in the hippocampus of the postnatal Guinea pig.

The present study tested the hypothesis that chronic prenatal ethanol exposure causes long-lasting changes in glucocorticoid signalling in postnatal offspring. Pregnant guinea pigs were treated with ethanol (4 g/kg maternal body weight/day), isocaloric-sucrose/pair-feeding or water throughout gestation, and maternal saliva cortisol concentration was determined 2 h after treatment at different stages of gestation. Electrically-stimulated release of glutamate and GABA, in the presence or absence of dexamethasone, as well as glucocorticoid and mineralocorticoid receptor mRNA expression, was determined in the hippocampus and prefrontal cortex of adult offspring of treated pregnant guinea pigs. Maternal saliva cortisol concentration increased throughout pregnancy, which was associated with increased foetal plasma and amniotic fluid cortisol concentration. Ethanol administration to pregnant guinea pigs increased maternal saliva cortisol concentration during early and mid-gestation. In late gestation, ethanol administration did not increase saliva cortisol concentration above that induced by pregnancy. Chronic prenatal ethanol exposure had no effect on stimulated glutamate or GABA release, but selectively prevented dexamethasone-mediated suppression of stimulated glutamate release, and decreased expression of mineralocorticoid, but not glucocorticoid, receptor mRNA in the hippocampus of adult offspring. These data indicate that maternal ethanol administration leads to excessively increased maternal cortisol concentration that can impact negatively the developing foetal brain, leading to persistent postnatal deficits in glucocorticoid regulation of glutamate signalling in the adult hippocampus.

Chronic prenatal ethanol exposure increases apoptosis in the hippocampus of the term fetal guinea pig.

It is hypothesized that chronic prenatal ethanol exposure (CPEE), via maternal ethanol administration, increases mitochondrial-directed apoptosis in the hippocampus of the term fetus that precedes loss of hippocampal CA1 pyramidal cells. To test this hypothesis, timed pregnant guinea pigs received chronic oral administration of: 4 g ethanol/kg maternal body weight/day, isocaloric-sucrose/pair-feeding or water throughout gestation. At gestational day 65 (term fetus) and postnatal day 0 (neonate), individual offspring were euthanized, and the brain was excised and dissected. CPEE, compared with the isocaloric-sucrose/pair-fed and water control groups, decreased the brain weight of the term fetus and neonate. CPEE did not alter the density of CA1 pyramidal cells in the hippocampus of the term fetus and neonate. In the term fetus, CPEE increased cytochrome c content in the cytosolic fraction of the hippocampus, altered the mitochondrial localization of cytochrome c in cells of the dorsal hippocampus, and increased the percentage of cells in the dorsal hippocampus containing activated caspase-3 and cleaved poly(ADP-ribose) polymerase. The data indicate that CPEE increases neuroapoptosis in the hippocampus of term fetus, which appears to occur via an intrinsic, mitochondrial-directed mechanism initiated by leakage of pro-apoptotic cytochrome c from mitochondria into the cytoplasm.

Health-related quality of life during four-layer compression bandaging for venous ulcer disease: a randomised controlled trial.

BACKGROUND: Venous leg ulceration is a chronic debilitating condition which negatively impacts on patients' quality of life. Despite the application of gold standard treatment a number of patients suffer from 'slow to heal' ulcers, which can require treatment for years. AIMS: The aim of this study was to compare the effects of four-layer compression bandaging (4LB) for treating venous leg ulcers with other available treatments on health-related quality of life duringtreatment. METHODS: In this pragmatic trial, 200 patients with venous leg ulceration were randomised either to 4LB (intervention group; n = 100) or to continue their usual system of care (control group; n = 100). Analysis was by intention to treat; quality of life measurements were taken at randomisation and after six weeks of treatment. RESULTS: 4LB provided greater quality of life benefits than the control group particularly in the area of physical activity and social functioning. CONCLUSION: Due to the long-term nature of treatment for many of these patients, the effects on quality of life should be considered when prescribing treatment. This study has shown that 4LB significantly improves the quality of life of patients during treatment for venous leg ulceration.

Spatial acquisition in the Morris water maze and hippocampal long-term potentiation in the adult guinea pig following brain growth spurt--prenatal ethanol exposure.

Previous work has demonstrated that in the guinea pig, chronic prenatal ethanol exposure throughout gestation can result in deficits in spatial learning in the Morris water maze and impaired hippocampal long-term potentiation (LTP). The behavioural effects are known to be dose dependent because water maze deficits occur at a dose of 4 g ethanol/kg maternal body weight/day, but not at a dose of 3 g/kg/day, administered throughout gestation. It is possible that the gradual, progressive development of tolerance to ethanol throughout gestation limits ethanol toxicity, especially for lower doses of ethanol. The present study examined whether neurobehavioural deficits are produced by prenatal ethanol exposure at a dose of 3 g/kg/day, administered only during the brain growth spurt (BGS), a regimen designed to limit the development of ethanol tolerance. Pregnant guinea pigs [term, about gestational day (GD) 68] received oral administration of ethanol (1.5 g/kg maternal body weight/day on GD 43 and 44 and then 3 g/kg maternal body weight/day from GD 45 to 62), isocaloric-sucrose/pair-feeding, or water. Offsprings were studied between postnatal days (PD) 40 and 80. The maternal blood ethanol concentration (BEC) on GD 57 or 58, at 1 h after the daily dose, was 245+/-19 mg/dl (n=7). This BGS--prenatal ethanol exposure regimen did not affect spatial learning performance in the Morris water maze over a 7-day test period or in the LTP recorded in the CA1 region of the hippocampus. Thus, even when limiting the development of ethanol tolerance seen with chronic ethanol treatment throughout gestation, ethanol exposure during the BGS does not result in deficits in the behavioural and electrophysiological measures of hippocampal integrity assessed in the present study. These data indicate that in the guinea pig, the BGS may not constitute a critical period of vulnerability for ethanol-induced deficits in spatial learning or hippocampal synaptic plasticity in young adult offspring.

Chronic prenatal ethanol exposure alters hippocampal GABA(A) receptors and impairs spatial learning in the guinea pig.

Chronic prenatal ethanol exposure (CPEE) can injure the developing brain, and may lead to the fetal alcohol syndrome (FAS). Previous studies have demonstrated that CPEE upregulates gamma-aminobutyric acid type A (GABA(A)) receptor expression in the cerebral cortex, and decreases functional synaptic plasticity in the hippocampus, in the adult guinea pig. This study tested the hypothesis that CPEE increases GABA(A) receptor expression in the hippocampus of guinea pig offspring that exhibit cognitive deficits in a hippocampal-dependent spatial learning task. Timed, pregnant guinea pigs were treated with ethanol (4 g/kg maternal body weight per day), isocaloric-sucrose/pair-feeding, or water throughout gestation. GABA(A) receptor subunit protein expression in the hippocampus was measured at two development ages: near-term fetus and young adult. In young adult guinea pig offspring, CPEE increased spontaneous locomotor activity in the open-field and impaired task acquisition in the Morris water maze. CPEE did not change GABA(A) receptor subunit protein expression in the near-term fetal hippocampus, but increased expression of the beta2/3-subunit of the GABA(A) receptor in the hippocampus of young adult offspring. CPEE did not change either [(3)H]flunitrazepam binding or GABA potentiation of [(3)H]flunitrazepam binding, but decreased the efficacy of allopregnanolone potentiation of [(3)H]flunitrazepam binding, to hippocampal GABA(A) receptors in adult offspring. Correlational analysis revealed a relationship between increased spontaneous locomotor activity and growth restriction in the hippocampus induced by CPEE. Similarly, an inverse relationship was found between performance in the water maze and the efficacy of allopregnanolone potentiation of [(3)H]flunitrazepam binding in the hippocampus. These data suggest that alterations in hippocampal GABA(A) receptor expression and pharmacological properties contribute to hippocampal-related behavioral and cognitive deficits associated with CPEE.

Chronic prenatal ethanol exposure impairs conditioned responding and enhances GABA release in the hippocampus of the adult guinea pig.

In this study, we assessed the effects of chronic prenatal ethanol exposure (CPEE) on spatial navigation in the water maze, conditioned responding using food-reinforced lever pressing, and amino acid neurotransmitter release from the hippocampus of the adult guinea pig. Pregnant guinea pigs were treated with ethanol (3 g/kg of maternal body weight/day), isocaloric-sucrose/pair-feeding, or water throughout gestation. Adult offspring were trained in two-lever operant chambers to respond for sucrose pellets, with one lever designated as the reward lever. There were no group differences in response acquisition or lever discrimination on a fixed-ratio 1 (FR-1) schedule. During extinction sessions, CPEE offspring maintained higher levels of responding on the previously reinforced lever, suggesting that CPEE increases perseveration and/or impairs response inhibition but does not affect operant responding for an appetitive reinforcer or the ability to discriminate rewarding from nonrewarding stimuli. In contrast, there was no effect of CPEE on performance in the water maze in the maternal ethanol regimen used in this study. CPEE did not alter electrically evoked glutamate or GABA release from hippocampal brain slices. However, when slices were tested after delivery of a tetanizing stimulation (five 5-s trains at 100 Hz), post-tetanic potentiation of electrically stimulated GABA release was greater in hippocampal slices obtained from CPEE offspring, whereas post-tetanic potentiation of electrically stimulated glutamate release was unaffected. These data suggest that conditioned learning is a sensitive behavioral measure of CPEE-induced brain injury. Increased activity-dependent potentiation of GABA release in the hippocampus may contribute to alterations in synaptic plasticity observed in CPEE offspring.

Effect of glucose and oxygen deprivation on heme oxygenase expression in human chorionic villi explants and immortalized trophoblast cells.

Although hypoxia induces heme oxygenase (HO)-1 mRNA and protein expression in many cell types, recent studies in our laboratory using human placental tissue have shown that a preexposure to hypoxia does not affect subsequent HO enzymatic activity for optimized assay conditions (20% O2; 0.5 mM NADPH; 25 microM methemalbumin) or HO-1 protein content. One of the consequences of impaired blood flow is glucose deprivation, which has been shown to be an inducer of HO-1 expression in HepG2 hepatoma cells. The objective of the present study was to test the effects of a 24-h preexposure to glucose-deprived medium, in 0.5 or 20% O2, on HO protein content and enzymatic activity in isolated chorionic villi and immortalized HTR-8/SVneo first-trimester trophoblast cells. HO protein content was determined by Western blot analysis, and microsomal HO enzymatic activity was measured by assessment of the rate of CO formation. HO enzymatic activity was increased (P < 0.05) in both placental models after 24-h preexposure to glucose-deficient medium in 0.5 or 20% O2. Preexposure (24 h) in a combination of low O2 and low glucose concentrations decreased the protein content of the HO-1 isoform by 59.6% (P < 0.05), whereas preexposure (24 h) to low glucose concentration alone increased HO-2 content by 28.2% in chorionic villi explants (P < 0.05). In this preparation, HO enzymatic activity correlated with HO-2 protein content (r = 0.825). However, there was no correlation between HO-2 protein content and HO enzymatic activity in HTR-8/SVneo trophoblast cells preexposed to 0.5% O2 and low glucose concentration for 24 h. These findings indicate that the regulation of HO expression in the human placenta is a complex process that depends, at least in part, on local glucose and oxygen concentrations.

Randomized clinical trial and economic analysis of four-layer compression bandaging for venous ulcers.

BACKGROUND: The aim of this study was to compare the cost-effectiveness of four-layer compression bandaging for venous leg ulcers with that of other available treatments. METHODS: In this pragmatic trial, 200 patients with a venous leg ulcer were randomized either to four-layer bandaging (intervention group; n = 100) or to continue their usual system of care (control group; n = 100). The follow-up for each patient was 12 weeks. Analysis was by intention to treat; the main outcome measures were time to healing and cost to the health board per leg healed. RESULTS: Baseline characteristics were well matched in the two groups. The Kaplan-Meier estimate of the healing rate at 3 months was 54 per cent with four-layer bandaging and 34 per cent in the control group. Throughout the 3 months, four-layer bandaging healed leg ulcers significantly earlier (P = 0.006). There was a significant reduction in the median cost per leg healed with four-layer bandaging (euro 210 versus euro 234; P = 0.040). CONCLUSION: Four-layer bandaging is currently the most effective method of treating venous leg ulcers in a community setting.

Effects of chronic prenatal ethanol exposure on cGMP content and glutamate release in the hippocampus of the neonatal guinea pig.

The glutamate-N-methyl-D-aspartate (NMDA) receptor-nitric oxide synthase (NOS)-cGMP signal transduction system plays key neurotrophic and intercellular communication roles in the hippocampus. In the guinea pig, chronic prenatal ethanol exposure (CPEE), via maternal ethanol administration, suppresses the hippocampal glutamate-NMDA receptor-NOS pathway in the near-term fetus and decreases stimulated glutamate release in the hippocampus of young postnatal offspring, with no effect on NMDA receptor number or NOS activity. At present, the effect of CPEE on cGMP, a key second messenger of the glutamate signal transduction system, in the hippocampus is not known. The objective of this study was to test the hypothesis that CPEE suppresses the hippocampal glutamate signal transduction system in the neonatal guinea pig at the levels of cGMP content and glutamate release. Timed pregnant guinea pigs received chronic oral administration of 4 g ethanol/kg maternal body weight/day, isocaloric-sucrose/pair-feeding, or water treatment throughout gestation. CPEE decreased brain and hippocampal weights at postnatal day (PD) 1 and PD 5 (P<.05). CPEE did not affect basal, NMDA (1, 10, or 100 microM)-stimulated, or K(+) (15 or 30 mM)-stimulated cGMP content in transverse hippocampal slices at PD 1 or 5. At 60 mM K(+), however, CPEE decreased stimulated hippocampal cGMP content at PD 1 (P<.05) and increased stimulated cGMP content at PD 5 (P<.05). In transverse hippocampal slices, CPEE did not affect basal or K(+) (40 or 45 mM)-stimulated glutamate release at PD 1 or 5, or NMDA (50 microM)-stimulated glutamate release at PD 1, but did decrease NMDA (50 microM)-stimulated glutamate release at PD 5 (P<.05). The data demonstrate that the effects of CPEE on stimulated cGMP content and glutamate release in the hippocampus of the neonatal guinea pig are stimulating agent- and age-dependent.

Effects of hypoxia on heme oxygenase expression in human chorionic villi explants and immortalized trophoblast cells.

Although hypoxia induces heme oxygenase (HO)-1 protein and mRNA expression in many cell types, hypoxia has also been shown to decrease HO-1 mRNA and protein expression. We tested the hypothesis that 24-h preexposure to hypoxia in human placental preparations suppresses HO protein expression and enzymatic function. Immortalized HTR-8/SVneo first-trimester trophoblast cells and explants of normal human chorionic villi (CV) from term placentas were cultured for 24 h in 1%, 5%, or 20% O(2). HO protein levels were determined by Western blot analysis, and microsomal HO activity was measured. HO-2 protein content was decreased by 17% and 5% in human trophoblast cells after 24-h exposure to 1% and 5% O(2), respectively, versus 20% O(2). In contrast, HO-2 protein content in CV explants was unaffected by changes in oxygenation. HO-1 protein content, which was barely detectable in both biological systems, was not affected by changes in oxygenation. Similarly, HO enzymatic activity was unchanged in both preparations after 24-h exposure to 1%, 5%, or 20% O(2). The above data do not support the hypothesis that hypoxia in the human placenta suppresses both HO protein content and HO protein function. The present observations reinforce the necessity to determine both HO protein expression and function.

Relationship between tissue damage and heme oxygenase expression in chorionic villi of term human placenta.

Heme oxygenase (HO) catalyzes the oxidation of heme to carbon monoxide (CO), biliverdin, and iron and is thought to play a role in protecting tissues from oxidative damage. There are three isoforms of HO: HO-1 (inducible), HO-2 (constitutive), and HO-3 (unknown function). Preeclampsia is characterized by an inadequately perfused placenta and areas of tissue damage. We hypothesized that damaged areas of placentas from women with PE and uncomplicated pregnancies are associated with an alteration in HO expression. Compared with microsomes isolated from morphologically normal and peri-infarct chorionic villi of pathological placentas, microsomes from infarcted chorionic villi from the same placentas had decreased HO activity measured under optimized assay conditions. There was no correlation between microsomal HO levels and activity and tissue damage in uncomplicated pregnancies. Whereas there was no significant difference in HO-1 protein levels across all regions of uncomplicated and mildly preeclamptic pregnancies, HO-2 protein levels were decreased (P < 0.05) in peri-infarct regions and infarcted chorionic villi of mildly preeclamptic pregnancies. Immunohistochemical analysis revealed an apparent decrease in both HO-1 and HO-2 protein expression in damaged tissues. HO-1 and HO-2 were immunolocalized in the syncytiotrophoblast layer of the chorionic villi, the underlying cytotrophoblast, and in the vascular endothelium. This study suggests that the ability of the chorionic villi to oxidize heme to CO, biliverdin, and iron may be compromised in areas of tissue damage in the placenta of women with preeclampsia.

Carbon monoxide decreases perfusion pressure in isolated human placenta.

Carbon monoxide (CO) is one of the metabolites formed via heme oxidation catalysed by the enzyme heme oxygenase (HO). Endogenous formation of CO, mediated by HO, has been noted in both placental and umbilical vessels. In blood vessels from different mammalian sources, it has been proposed that the vasodilator effect of CO is mediated via stimulation of soluble guanylyl cyclase (sGC) and consequent increased cGMP formation. The purpose of the present study was to determine the effect of exogenous CO on placental cotyledon perfusion pressure and to determine the role of sGC in the CO-induced decrease of perfusion pressure using the in vitro human placental perfusion preparation. A thromboxane A2 mimetic (U46619) was added to the foetal perfusion medium to constrict the placental blood vessels. Carbon monoxide was added to the foetal perfusion medium in increasing concentrations to determine its effect on placental perfusion pressure. Carbon monoxide produced a concentration-dependent decrease in placental perfusion pressure. The addition of ODQ, a sGC inhibitor, attenuated the CO-induced decrease in placental perfusion pressure, while addition of YC-1, an activator of sGC, augmented the CO-induced decrease in placental perfusion pressure. The data indicate that CO causes vasorelaxation of placental resistance blood vessels, in large part, via activation of sGC.

Impaired acquisition in the water maze and hippocampal long-term potentiation after chronic prenatal ethanol exposure in the guinea-pig.

In the hippocampus, the CA1 region is selectively vulnerable to the effects of chronic prenatal ethanol exposure. In the guinea-pig, the number of CA1 pyramidal cells is decreased after chronic prenatal ethanol exposure. We tested the hypotheses that chronic prenatal ethanol exposure (through maternal ethanol ingestion) results in impairments in spatial learning and short- and long-term plasticity in the CA1 region of the postnatal guinea-pig hippocampus. Timed, pregnant guinea-pigs were treated with ethanol (4 g/kg maternal body weight/day), isocaloric sucrose/pair-feeding, or water throughout gestation. Offspring were studied between postnatal days 40 and 80. In the Morris water maze, animals exposed to ethanol prenatally showed slower acquisition of an escape response to a hidden platform over 5 days of training. The amplitude of the field excitatory postsynaptic potential in the CA1 region in response to contralateral CA3 stimulation was decreased in offspring exposed to ethanol prenatally. Two forms of short-term plasticity (paired-pulse and frequency facilitation) were unaffected by chronic prenatal ethanol exposure. Long-term potentiation (LTP) in response to high-frequency CA3 stimulation was induced reliably and maintained over 60 min in isocaloric-sucrose and water control animals. However, LTP failed to be induced in the CA1 area of the hippocampus in prenatal ethanol-exposed offspring. These data show that chronic prenatal ethanol exposure, through maternal ethanol administration, impairs spatial performance and LTP in CA1 neurons. Hippocampal dysfunction could contribute importantly to the cognitive and behavioural deficits resulting from chronic prenatal ethanol exposure.